Transcript Hearing Assistive Technologies for Deaf and Hard of Hearing children

Hearing Assistive Technologies for
Deaf and Hard of Hearing Children
Perry C. Hanavan, Au.D.
Midwest Conference on Deaf Education
Sioux Falls, SD
July 11-12, 2011
HA Developments
• Nanotechnology providing water resistant hearing
aids
HA Directional Microphones
• Most HA have directional microphones
• Proven beneficial technology
• Data support use of directional hearing aids in some
noisy school environments
• Suggest use of directional mode should be limited to
situations in which all talkers of interest are located
in front of the student.
(Ricketts & Galster 2007)
HA Digital Feedback Reduction
• Technology has dramatically
improved the reduction of
acoustic feedback
• Helps increase HA gain
without “whistle”
HA Digital Noise Reduction
• Significant increase in “ease of listening” with DNR
(Bentler, Wu, Kettel & Hurtig 2008)
• Spectral changes from noise suppression ALWAYS
improve speech.
– Therefore, we tentatively recommend DNR systems be
routinely enabled for children of all ages…just like adults.
(Dillon, Ching & Golding 2008)
• DNR does NOT have negative effect on perception of
nonsense syllables, words or sentences
– Stelmachowicz et al 2010)
HA Extended HF Frequency Bandwidth
Stelmochowitz found bandwidth beyond 5 kHz
(Stelmachowicz et al 2004)
(Stelmachowicz 2010)
Pittman found that children with HL require 3X the exposure to
learn each new word and concepts due to reduced acoustic
bandwidth caused by HL
(Pittman 2008)
• Most modern HA have bandwidth from 6 to 10 plus kHz
• However telecoil use may only amplify to 4 kHz
• Thus FM technology for speech and language develop may be
better than telecoil-induction loop technology
• However telecoil option remains critically import for:
– Phone
– More public facilities (churches, theaters, sports arenas, etc.) are
getting looped (Get in the Loop initiative) AAA, HLAA, Sertoma
10,000 kHz Bandwidth
Bandwidth & Phoneme ID in Students
CAM2
• CAM2 software prescribes the amount of amplification of
high-frequency sounds above 6000 Hz-required to
restore audibility
• Most HA software only prescribes amount of
amplification to 6000 Hz
• Higher frequencies help distinguish sounds such as “sh”,
“ch” and “f”
• Listening situations, such as in a room where several
people are speaking at once—higher frequencies make it
much easier to understand the person you want to
listen/hear.
• Higher frequencies can improve sound localization
Loops &Telecoils-What Is It?
Telecoil--Advantages
• Universal
• Convenient--no additional apparatus, special
equipment , streamers, remotes, etc.
• No battery drain
• No pairing – universal signal worldwide/standardized
• Most HA have T/TM/M options for classroom use
• Inexpensive (little or no cost to parents)
• No time delay from microphone to HA
• Can accommodate hundreds of listeners in the loop
• Most HA and all CI have telecoil
• Used with all landline phones, many cell phones with
T3/T4 ratings
HA with Telecoils
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7 of 28 CIC
8 of 10 ITC
20 of 42 RIC/RITE
24 of 35 “Slim- & Thin-Tube” HA
38 of 38 ITE
29 of 30 BTE
(Oct 2010)
(May/Jun 2009)
(Jan 2010)
(Feb 2010)
(Sep 2010)
(Jan 2009)
Telecoil Available for CI
Telecoil—Frequency Response
• Currently, frequency response characteristics limited
in low and high frequencies (decreased bandwidth)
Telecoil—Orientation
• Telecoil situated
perpendicular to installed
loop wire or telephone
• Incorrect orientation of
telecoil results in attenuated
signal
• Head orientation and tilting
head may result in poor
signal reception
• Placement not ideal for
landline phone
Orientation & Frequency Response
CI Telecoil Orientation
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MED-EL Opus 2:
Advanced Bionics Harmony:
Cochlear Nucleus 5:
Cochlear Nucleus Freedom:
Vertical
45 deg angle
Horizontal
Vertical
Looping Options Beyond the Classroom
• School
– Auditorium
– School secretary office
– Librarian desk
• Community
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Church
Grocery store checkout
Library checkout
Transportation
Ticket booths
Drive-up windows
Frequency Lowering HAs
• Studies show that frequency lowering aids improve
speech recognition with severe to profound high
frequency SNHL
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Simpson et al, 2005
Glista et al, 2009
Nyffeler 2008
Wolfe et al, 2010
Wolfe et al 2011
• “Non-linear frequency compression algorithm is the most
important development in pediatric amplification in over
a decade.”
(Richard Seewald)
Non-Linear Frequency Lowering
High Frequency Loss
• Phonak (Naida) and Widex (Inteo) hearing aids
• Frequency lowering (frequency transposition)
hearing aids for persons with un-aidable high
frequency hearing loss.
• Creates new acoustic cues for hearing /s/ sound
important in plurals (e.g., books, it’s)
• Speech recognition cues improve over time from
initial fit
• Students function better in classroom and in various
communication situations
(Glista et al 2009)
High Frequency Lowering Compression
• NLFC improves speech recognition and speech
production for children with moderate to profound
hearing loss
• NLFC should be considered for all children moderate
to profound high-frequency hearing loss
• Verification is essential for success of these children
• Kids with essentially no hearing above 1500 Hz
should be referred for CI evaluation
(Wolfe et al 2010)
Hearing Tests for High Frequency
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University of Western Ontario Plurals Test
Phonak Logatome Test
BKB-SIN
Recorded /sh/ and /s/, University Western Ontario
UWO Plural Test
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Recorded test
Open set test
Female speaker
15 words familiar to school-aged children in both
singular and plural form (/s/ or /z/ in final position)
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Skunk/skunks
Book/books
Fly/flies
Crayon/crayons
• Presented at 50 dB SPL from loudspeaker 1 meter
directly in front of child
UWO /s/--/sh/ Video Game
Phonak Logatom Test
• Adaptive, computer controlled test
• Developed by Phonak
• Female speaker: “My name is…”
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ASA
ASA (filter to 6 kHz)
ADA
AKA
AFA
ASHA
ATA
• Software track level in dB SPL that corresponds to 50%
correct performance
BKB-SIN
BKB-SIN
• 10 sentences presented
twice
• Increasing noise with each
sentence
• Indicates ability to
understand speech in noise
• Helps audiologist select
appropriate hearing aid and
hearing assistance
technologies
RITA, RIC & MARIC
• RITA
Receiver in the aid
• RIC
Receiver in canal
• MARIC
Mike and receiver in canal
HA Streamers
• Bluetooth streamers/Remote controls
• System that allows HA to connect with virtually any
audio device – cell phones, IPods, PDAs, TV, etc.
• Short distance wireless communication
• Can be worn around neck or held in hand
• Battery drain increase
• No standardization between various HA
manufacturers
Personal FM
• FM/Radio Frequency Devices
• The benefits of FM systems are well documented and
include:
– Eliminating negative effects of noise and reverberation on
speech perception, and
– maintaining constant speech input regardless of distance
between the speaker and listener
• (Boothroyd, 2004; Chisholm et al, 2007).
– FM use specifically with cochlear implants, the overwhelming
majority of these studies pertain to children in educational
setting (Davies et al, 2001; Schafer & Thibodeau, 2006).
– Research with children has shown significant improvement in
speech understanding in noise when an FM system is used in
conjunction with a cochlear implant (Davies et al, 2001; Schafer
& Thibodeau, 2006).
Personal Adaptive (Dynamic) FM
• On the objective measures, Phonak
adaptive FM processing resulted
in significantly better speech
recognition in noise compared to
fixed FM processing for 68- and 73dBA noise levels.
• On the subjective measures, all
individuals preferred adaptive over
fixed processing for half of the
activities.
• Adaptive processing was also
preferred by most (8–9) individuals
for the remaining 4 activities.
(Thibodeau 2010)
Phonak FM Recievers
Binaural CI Advantages
CIs and FM Systems
• Remote Microphone
• Bilateral Wireless Systems
• Includes HA for non-CI ear if aidable with remote
microphone
• Meta-analysis:
– Classroom amplification systems (3% improvement — not
significant improvement)
– Desktop amplification systems (17% improvement—
significant improvement)
– Personal FM systems—38% improvement—significant
improvement over the other two)
(Schafer & Wolfe 2010)
Note FM component on CI
MLxi Universal Receiver
• Phonak’s universal Dynamic FM receiver.
• When attached to the user’s hearing
instrument, MLxi provides all the benefits of
Phonak’s Dynamic FM technology.
• Dynamic Speech Extractor - an algorithm that
improves signal-to-noise ratios by up to 15 dB
and speech scores in noise by dozens of
percentage points.
• Fully automated product; the user just needs
to switch it on; child-proof and backwards
compatible
• Compatible with virtually all BTEs and cochlear
implants
• Compatible with all Phonak transmitters
CI Performance in Noise w/o FM
CI plus Personal FM
• Personal FM system have been used to assist HA users for
improving hearing in difficult listening environments
• Personal FM systems are the most effective means to
assist CI users to hear better in noise (Wolfe & Schafer,
2008; Wolfe et al, 2009)
• Audiologists have been reluctant to consider personal FM
because:
– Multiple parameters that must be adjusted with some FM
systems including:
• Ratio of the FM input to the processor mic input (i.e.,
Mixing Ratio)
• Gain of the FM receiver
• Input Dynamic Range (IDR)
CIs and FM Systems
• Meta-analysis
– HA or CI on 2nd ear (bilateral)—1.1 dB improvement on
average
– CI with FM on one side—13.3 dB improvement
– 2nd CI or HA on second side—
– Binaural FM—best signal option (Dynamic FM will
improve listening in noise, social situations, restaurants,
etc.)
• Recommendation:
– If family/school can afford, best option is binaural Dynamic
FM with binaural CI or CI and HA
– Next best option is Dynamic FM on 1st cochlear implant
side
(Wolfe 2010)
Classroom Soundfield Amplification
• Benefits
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Children with temporary HL
Improve S/N ratio
Reduce teacher vocal fatigue
Children with APD and ADHD (hearing in noise)
Improves academic achievement and behavior
Increased word and sentence recognition
Improves literacy growth
• Disadvantages
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Do not use in place of Dynamic FM for HA and CI users
Will not compensate for poor classroom acoustics
Poor installation/systems may not be helpful
Poor microphone management by teacher not helpful
Unclear speech by teacher not helpful
Classroom Amplification Systems
Self install systems:
• LightSpeed
REDCAT
• Phonak
Dynamic SoundField
Phonak Dynamic Soundfield
• Inspiro Dynamic microphone
• Compatible with Dynamic FM
receivers, BAHA, other HA
• Software updatable
• Remote computer access
• Monitors classroom environment
and adjusts volume and
frequency
• Provides optima S/N ratio
• Connects to Smartboard
Questionnaire/Inventory/Survey
• Adolescent SAC / SOAC
Questionnaire
• SSQ
• Listening Inventories For
Educators (L.I.F.E.)
• Children’s Auditory
Performance Scale (CHAPS)
• SIFTER
• CHILD
• ELF
Go to www.hear2learn.com for
additional surveys
Ling 6 Sound Check
• Evaluate student at
variety of distances
to determine
maximum distance
Ling sounds heard
• Ling 6 Sound Check
Chart
• Ling 6 Behavioral
Daily Checklist
• Ling 6 Recording
Chart
Functional Listening Evaluation
• Determine how listening abilities are affected by noise,
distance, and visual input in an individual’s natural listening
environment
• Designed to simulate listening ability in situations that
represent actual listening conditions in student’s classroom–
not sound booth
• Administration of the evaluation, the student’s teachers,
parents, and others gain understanding affects of adverse
listening conditions encountered by the student.
• The evaluation results are also useful in justifying
accommodations, such as assistive listening devices, sign
language or oral interpreters, notetakers, captioning, special
seating, and room acoustic modifications.
• Functional Listening Evaluation
(Ying , 1990), (Ross, Bracken & Maxon, 1992)
FLE (cont.)
• Test administration takes approximately 30 minutes,
including set up, with sentences and 20 minutes with
words.
1. Auditory-Visual
Close
Quiet
2. Auditory
Close
Quiet
3. Auditory-Visual
Close
Noise
4. Auditory
Close
Noise
5. Auditory-Visual
Distant
Noise
6. Auditory
Distant
Noise
7. Auditory
Distant
Quiet
8. Auditory-Visual
Distant
Quiet
Practical Hearing Aid Skill Tasks
(PHAST)
• Can student and parents pass the PHAST?
• Perhaps modify this for use with assistive devices?
(Desjardins & Doherty 2009)
HA Functioning in Preschool Setting
• Over half of the HA tested were determined to have
at least one or more problems
• Problems detected using listening and visual checks
• Failure rates based on basic listening and visual
checks among the HA examined in this study
demonstrate no improvement over those reported in
the 1970''s
• The results re-emphasize the need for a national
dialogue on this topic
(Burkhalter et al 2011)